The reason that TurboTax said that you will receive back $1,700 is because you never received any stimulus payments. The stimulus is an advance payment of the recovery rebate credit.
The "recovery rebate" tax credit and stimulus checks are two parts of the same thing. The way the law is written, both the first ($1,200) and second ($600) stimulus checks were simply advance payments of the credit. So, if the combined total of your two stimulus checks (i.e., advance payments) is less than the recovery rebate credit amount, you may be able to get the difference back on your 2020 tax return in the form of a larger tax refund or a lower tax bill.
@Karryn1313
